CNH: Competing Demands and Future Vulnerability of Groundwater: Drinking Water Quality and Food Security in Arsenic-Impacted South and Southeast Asia

CNH：地下水的竞争需求和未来脆弱性：受砷影响的南亚和东南亚的饮用水质量和粮食安全

• 批准号: 1414131
• 负责人: Alexander van Geen
• 金额: $ 145万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1414131&HistoricalAwards=false
• 关键词: CNH; Competing; Demands; Future; Vulnerability

Hundreds of millions of people worldwide are exposed to dangerous arsenic (As) levels by drinking untreated groundwater. As contamination causes a variety of severe health problems in humans, including several forms of cancer and increased infant mortality Recent field evidence shows how human activities can elevate As concentrations and suggests many more people could be affected in the coming decades. Massive groundwater pumping for the supply of both megacities and rice irrigation could contaminate deep aquifers that currently have low levels of As, by drawing in groundwater that is high in As. Furthermore, irrigation with high-As groundwater markedly reduces the yield of rice crops, threatening food security. The extent of groundwater contamination in affected areas is determined by a combination of individual farmers' practices and the decisions made by large municipalities. In order to study these interactions, the researchers will model how human decisions affect As levels in aquifers across three river basins that have experienced differing degrees of development. The study will identify effective measures to reduce the amounts of As in groundwater and rice crops, leading to safer food and water supplies. Aquifer vulnerability will be assessed by tracking the penetration of the radioisotopes of hydrogen in water and carbon released to the atmosphere between 1950 and 1970 relative to As in groundwater. Several hundred wells distributed along three 30 km transects, some affected by municipal and irrigation pumping and others not, will be sampled for these and additional tracers. These measurements will be combined with modeling of groundwater flow and As transport to determine whether irrigation pumping or municipal pumping poses a more serious threat. Farmer behavior will be assessed through a randomized controlled trial by providing field-kits for measuring As in irrigation water and paddy soil in some villages and not in others. Currently all rice farmers in the study area use some fertilizer to boost yields, but almost no farmer removes the most contaminated topsoil to reduce As before adding fertilizer and increase yields for years to come. The researchers will examine the tradeoff between a short-term gain and a long-term gain where the one-time investment cost is paired with varying patterns of future benefits. The observations are expected to establish that soil removal and lowering of As in irrigation water will increase rice yields and protect deep low-As groundwater for drinking. More broadly, the research is expected to provide evidence for policy makers that scaling up the adoption of simple alternative approaches can protect groundwater aquifers.

全世界数亿人因饮用未经处理的地下水而暴露于危险的砷（As）水平。由于污染会导致各种严重的人类健康问题，包括几种形式的癌症和婴儿死亡率增加最近的实地证据表明，人类活动如何提高As浓度，并表明在未来几十年内可能会有更多的人受到影响。大规模抽取地下水供应特大城市和水稻灌溉可能会污染目前砷含量低的深层含水层，因为抽取的地下水砷含量高。此外，灌溉高砷地下水显着降低水稻作物的产量，威胁粮食安全。受影响地区地下水污染的程度取决于个别农民的做法和大城市的决定。为了研究这些相互作用，研究人员将模拟人类的决定如何影响三个经历了不同发展程度的流域的含水层中的As水平。这项研究将确定有效的措施，以减少地下水和水稻作物中的砷含量，从而使食品和水供应更安全。将通过跟踪1950年至1970年期间相对于地下水中的砷，水中氢的放射性同位素和释放到大气中的碳的渗透情况，评估含水层的脆弱性。将对分布在沿着3个30 km样带的数百口威尔斯井进行取样，以获取这些和其他示踪剂，其中一些井受到市政和灌溉抽水的影响，另一些井则没有。这些测量将结合地下水流和As运输的建模，以确定灌溉抽水或市政抽水是否构成更严重的威胁。农民行为将通过随机对照试验进行评估，通过提供现场工具包测量灌溉水和水稻土中的砷在一些村庄，而不是在其他。目前，研究地区的所有稻农都使用一些肥料来提高产量，但几乎没有农民在添加肥料和提高产量之前清除污染最严重的表土。研究人员将研究短期收益和长期收益之间的权衡，其中一次性投资成本与未来收益的不同模式相结合。这些观察结果预计将确定土壤去除和降低灌溉水中的砷含量将增加水稻产量，并保护深层低砷地下水供饮用。更广泛地说，这项研究有望为政策制定者提供证据，证明扩大采用简单的替代方法可以保护地下水含水层。